Personality • What is it?

Personality Intro Psychology Georgia Tech Instructor: Dr. Bruce Walker

Measurement • Assessments can be structured or unstructured – Structured - long list of questions answered by the person. – MMPI - Minnesota Multiphasic Personality Inventory - 550 questions directed at 10 scales (subtests) each measuring a different aspect of personality

MMPI • Examples – Depression - “I often feel that life is not worth living” – Paranoia - “Several people are following me everywhere” – Schizophrenia - “I seem to hear things that other people cannot hear” – Psychopathic deviance - “I often was in trouble in school although I did not understand for what reasons.

– Traits - “the way that a person is” – Behavioral consistency

• Can it be measured? (reliability) • Does it really predict behavior? (validity)

MMPI • Items on this test were selected because the item distinguished between “normal” and hospitalized psychiatric patients • Assumption is that psychiatric patients were just extreme examples of a continuum of different personality types.

MMPI • How do you know that people are responding truthfully? – includes items where truthful answers are known but people intentionally lying might answer differently – “I sometimes gossip with other people” – If too many of these are answered “incorrectly” then the test results can be flagged as invalid.

MMPI • Result of test is a profile that reveals the components of one’s personality (supposedly)

How do we know that we’re actually measuring personality? • Predictive validity – Does a high score on “extroversion” actually predict the person’s behavior at a party? – Generally the predictive validity of personality measures is lousy. – Correlation between “extroversion” and # of people talked to at party .2 to .3

How do we know that we’re actually measuring personality? • Construct validity

How do we know that we’re actually measuring personality? • Construct validity

– But, if we look at the general pattern of relationships, the scales do show a some consistent relationship with the construct (e.g., extroversion)

– Psychopathic deviance (MMPI subscale)

Unstructured personality tests

Unstructured personality tests

• Projective techniques - present ambiguous stimulus and individual will “project” some kind of structure that reflects underlying psychological characteristics

• shallow emotional ties, disregard for social mores, failure to consider potential dangers and consequences of their own actions • High PD’s rated “least responsible” by classmates, more likely to be involved in drunk driving accidents

• Free association • Rorschach Inkblot tests • Thematic Apperception Test • Lousy validity, poor reliability, little increment over other methods.

Situation versus traits • Mischel - measures of supposedly stable traits seem to have little ability to predict behavior across different situations (r=+.3) – Honesty measures may predict probability of cheating on a test, but not probability of cheating at home, at work, etc. – Situations seem to drive behavior more than an internal characteristic of the individual.

Situation versus traits • Fundamental attribution error – If a person’s behavior is really dependent on the situation, why does “personality” seem so intuitively appealing? – People consistently attribute behavior of a person to “disposition” rather than to the context.

Situation versus traits – Example: People are given essays to read that argue either a pro-Castro or an anti-Castro position regarding Cuba. – People then asked to assess the writer’s opinion on Castro – Half of the people are told that position was freely selected by author, Half told that their position was assigned.

• Fundamental attribution error (Jones & Harris, 1967) estimate of writers attitude

• Fundamental attribution error

Situation versus traits

Choice Pro-Castro Anti-Castro No choice

pro

Situation versus traits • Taken to an extreme, Mischel might be suggesting that there is no such thing as “personality”

anti

Situation versus traits

• but... the controversy has been about consistency over situation

• Problem is one of “sample size”. We need to see a person act in many different situations

• Consistency over time is fairly high - ratings of “dependability” of males in high school correlate +.55 with ratings by different judges, 10 years later.

• Person by environment interactions

Theoretical descriptions of personality • Eysenck’s 2 dimensional Trait Theory

• Norman’s “Big Five” factors

• Neuroticism (Stable-unstable) • Extroversion Introversion

Where does personality come from? • Hereditary component – Twin studies - correlation of .5 between identical twins on scales of Neuroticism (but note that identical twins are also treated very similarly) – Disposition of adopted children correlated with biological parents (+.3) but not adoptive parents (+.05)

Introversion/Extroversion • Eysenck - introverts are more reactive to stimuli than are extroverts • Bullock & Gilliland (1993) - measured evoked brain potentials to auditory clicks, introverts show larger response than extroverts

Introversion/Extroversion

Introversion/Extroversion

• Introverts and Extroverts seek similar levels of arousal

• Introverts and Extroverts seek similar levels of arousal

• It takes less stimulation for introverts to reach optimal levels of arousal, thus preference for quieter activities

• Note that this can be reinforcing: less social activity, less practice socializing, social activities become even more arousing. (of course, there are limits...)

Social learning approach to personality development • Albert Bandura, Stanford University

• What is the influence of others’ behavior during development?

Social learning approach to personality development • Classic study – Children after viewing the video – Children shown the “beating up bobo” video were more aggressive, imitated the aggressive behavior and did a considerable amount of “novel” violent behavior.

Social learning approach to personality development

Social learning approach to personality development • Classic study – What is the influence of the behavior that you are exposed to on your own behavior? – This study triggered the TV violence debate – 36 boys, 36 girls, mean age 4.5 years – Viewed a video of an adult beating up a bobo doll or just playing with the doll

Social learning approach to personality development • Classic study – Children after viewing the video – Children shown “playing with bobo” video played with doll but did very little imitation of modeled behavior.

Social learning approach to personality development

• Classic study – Boys were more aggressive after watching Male on video, girls more when watching a Female.

• Considerable evidence that exposure to behaviors (not just violent) exerts a strong influence on children’s behavior • Such behaviors may set the stage for behavioral patterns later in life.